The invention is directed to devices for exercising and rehabilitating joints. More particularly, the invention relates to a controllable device for rehabilitation of the hand and wrist.
Joint dysfunction may result from injury, trauma, illness or other causes and usually requires, among other therapies, some physical rehabilitation involving range of motion and strength exercise of the affected joint. Prior devices for joint exercise are large, expensive, stationary machines, and as a result, are typically available only at clinics or therapists' offices. A patient must schedule and make visits to use the machines, which inconveniently requires travel by the patient to the clinic and limits the time and frequency with which a patient can perform rehabilitation. There is a need, therefore, for a rehabilitation device that can be carried to and used at a patient's home or other convenient place.
In addition, hand and wrist injuries are more common today than in past years with the wide spread use of computer keyboards and other devices involving repeated movements with strained hand and wrist positioning. An alternative to the large, expensive rehabilitation devices is desirable for hand and wrist rehabilitation.
The invention provides a device for rehabilitative exercise that includes a portable housing that can be carried by hand for use at a convenient place for the patient. The device includes a controllable resistance device contained within the portable housing, and clamps for mounting the device to a table or other structure.
The housing is of a size that can be carried by hand, and the controllable resistance device and control electronics are relatively light weight, all of which provide a hand-holdable portable device.
According to the invention, the controllable resistance device is preferably a rotary magnetorheological fluid brake having a rotatable disk mounted in a housing with a carrier fluid and dispersed magnetic particles. The device includes a controller that allows the patient to set the level of resistance provided by the brake.
The brake includes a shaft on which a tool providing a grip can be mounted. According to a preferred aspect of the invention, the device includes a plurality of interchangeable tools, each providing a different grip for the fingers and/or hand. In addition, different finger, hand, and wrist movements are provided by the tools. For example, pronation/supination of the wrist is provided by a tool having a cylindrical grip similar to a shovel handle perpendicular to the rotary brake shaft. Abduction/adduction of the hand and wrist is provided by a large disk shaped tool mounted perpendicularly on the shaft, or a bulb similar to a door knob mounted to the shaft. In addition, flexion/extension of the wrist is provided by a tool having a cylindrical grip similar to a bicycle handle aligned with the brake shaft.
According to another aspect of the invention, the tools are releasably mountable to the device with, for example, a spring ball arrangement that allows the tools to be snapped onto a shaft of the resistance device and snapped off the shaft for easy removal.